Systems and methods for enabling transmission of phase detection data

ABSTRACT

An electronic device is described. The electronic device includes an image sensor that is configured to capture phase detection data for automatic focusing. The electronic device also includes an automatic focusing module that is configured to dynamically enable or disable transmission of the phase detection data from the image sensor. The automatic focusing module may be configured to enable transmission of the phase detection data from the image sensor in response to detecting a scene change.

TECHNICAL FIELD

The present disclosure relates generally to electronic devices. Morespecifically, the present disclosure relates to systems and methods fordynamically enabling and disabling transmission of phase detection datafrom an image sensor.

BACKGROUND

Electronic devices (smartphones, cellular telephones, tablet computers,digital cameras, wireless modems, computers, digital music players,Global Positioning System units, Personal Digital Assistants, gamingdevices, etc.) have become a part of everyday life. Small computingdevices are now placed in everything from vehicles to housing locks. Thecomplexity of electronic devices has increased dramatically in the lastfew years. For example, many electronic devices have one or moreprocessors that help control the device, as well as a number of digitalcircuits to support the processor and other parts of the device.

In some cases, an electronic device may be used to capture digitalimages. As part of capturing digital images, the electronic device mayperform autofocus operations. The autofocus operations may use phasedetection (PD) data to focus a lens. However, transmitting andprocessing PD data requires a considerable amount of power. As can beobserved from this discussion, systems and methods for dynamicallyenabling and disabling the transmission of phase detection data may bebeneficial.

SUMMARY

An electronic device is described. The electronic device includes animage sensor that is configured to capture phase detection data forautomatic focusing. The electronic device also includes an automaticfocusing module that is configured to dynamically enable or disabletransmission of the phase detection data from the image sensor.

The automatic focusing module may be configured to enable transmissionof the phase detection data from the image sensor in response todetecting a scene change. The automatic focusing module may beconfigured to detect a scene change based on one or more of a gyroscopeoutput, automatic exposure control (AEC) exposure information, a sum ofabsolute differences or digital image correlation. The automaticfocusing module may be configured to disable transmission of the phasedetection data from the image sensor until detecting a scene change.

The automatic focusing module may be configured to analyze the phasedetection data to determine a lens position after enabling transmissionof the phase detection data from the image sensor in response todetecting a scene change. The automatic focusing module may also beconfigured to subsequently disable transmission of the phase detectiondata from the image sensor.

The automatic focusing module may be further configured to perform afine search to determine a final lens position after disablingtransmission of the phase detection data from the image sensor. Theautomatic focusing module may be configured to perform the fine searchto determine a final lens position based on image data from the imagesensor without the phase detection data.

The electronic device may also include an image signal processor that isconfigured to receive image data and the phase detection data from theimage sensor when transmission of the phase detection data from theimage sensor is enabled. The image signal processor may also beconfigured to receive image data from the image sensor when transmissionof the phase detection data from the image sensor is disabled.

The electronic device may also include an image signal processor that isconfigured to receive phase detection data from the image sensor whentransmission of the phase detection data from the image sensor isenabled. The image signal processor may also be configured to receiveimage data from the image sensor when transmission of the phasedetection data from the image sensor is disabled.

A method is also described. The method includes capturing, by an imagesensor, phase detection data for automatic focusing. The method alsoincludes dynamically enabling or disabling, by an automatic focusingmodule, transmission of the phase detection data from the image sensor.

An apparatus is also described. The apparatus includes means forcapturing, by an image sensor, phase detection data for automaticfocusing. The apparatus also includes means for dynamically enabling ordisabling, by an automatic focusing module, transmission of the phasedetection data from the image sensor.

A non-transitory tangible computer readable medium storing computerexecutable code is also described. The computer readable medium includescode for causing an image sensor to capture phase detection data forautomatic focusing. The computer readable medium also includes code forcausing an automatic focusing module to dynamically enable or disabletransmission of the phase detection data from the image sensor.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram illustrating an electronic device configuredto dynamically enable and disable transmission of phase detection (PD)data from an image sensor;

FIG. 2 is a flow diagram illustrating a method for dynamically enablingand disabling transmission of PD data from an image sensor;

FIG. 3 is a block diagram illustrating another configuration of anelectronic device configured to dynamically enable and disabletransmission of PD data from an image sensor;

FIG. 4 is a flow diagram illustrating another configuration of a methodfor dynamically enabling and disabling transmission of PD data;

FIG. 5 is a flow diagram illustrating yet another configuration of amethod for dynamically enabling and disabling transmission of PD data;

FIG. 6 is a block diagram illustrating another configuration of anelectronic device configured to dynamically enable and disabletransmission of PD data;

FIG. 7 is a block diagram illustrating yet another configuration of anelectronic device configured to dynamically enable and disabletransmission of PD data; and

FIG. 8 illustrates certain components that may be included within anelectronic device.

DETAILED DESCRIPTION

Various configurations are described with reference to the Figures,where like reference numbers may indicate functionally similar elements.The systems and methods as generally described and illustrated in theFigures could be arranged and designed in a wide variety of differentconfigurations. Thus, the following more detailed description of severalconfigurations, as represented in the Figures, is not intended to limitscope, but is merely representative.

FIG. 1 is a block diagram illustrating an electronic device 102configured to dynamically enable and disable transmission of phasedetection data 110 from an image sensor 106. The electronic device 102may also be referred to as a wireless communication device, a mobiledevice, mobile station, subscriber station, client, client station, userequipment (UE), remote station, access terminal, mobile terminal,terminal, user terminal, subscriber unit, etc. Examples of electronicdevices 102 include laptop or desktop computers, digital cameras,cellular phones, smart phones, wireless modems, e-readers, tabletdevices, gaming systems, robots, aircraft, unmanned aerial vehicles(UAVs), automobiles, etc. Some of these devices may operate inaccordance with one or more industry standards.

The electronic device 102 may be configured to perform automaticfocusing (AF) operations. The term “automatic focusing” may also bereferred to as autofocus, autofocus or the like.

In an implementation, an electronic device 102 may include one or morecameras 104. A camera 104 may include an image sensor 106 and an opticalsystem 112. The optical system 112 may include one or more lenses 114that focus images of objects that are located within the field of viewof the optical system 112 onto the image sensor 106. The focus of thelens 114 on the image sensor 106 may be determined by a lens position.

In an implementation, the electronic device 102 may also include acamera software application and a display screen. When the cameraapplication is running, image data 108 of objects that are locatedwithin the field of view of the optical system 112 may be recorded bythe image sensor 106. The image data 108 may be stored in a memorybuffer 116. In some implementations, the camera 104 may be separate fromthe electronic device 102 and the electronic device 102 may receiveimage data 108 from one or more cameras 104 external to the electronicdevice 102. In yet another implementation, the electronic device 102 mayreceive image data 108 from a remote storage device.

To capture the image data 108, an image sensor 106 may expose imagesensor elements to the image scene. The image sensor elements withinimage sensor 106 may, for example, capture intensity values representingthe intensity of the light of the scene at a particular pixel position.In some cases, each of the image sensor elements of the image sensor 106may only be sensitive to one color, or color band, due to the colorfilters covering the image sensor elements. For example, the imagesensor 106 may include an array of red, green and blue (RGB) filters.The image sensor 106 may utilize other color filters, however, such ascyan, magenta, yellow and key (CMYK) color filters. Thus, each of theimage sensor elements of the image sensor 106 may capture intensityvalues for only one color. The image data 108 may include pixelintensity and/or color values captured by the image sensor elements ofthe image sensor 106.

Although the present systems and methods are described in terms ofcaptured image data 108, the techniques discussed herein may be used onany digital image. For example, the image data 108 may be acquired fromframes from a video sequence. Therefore, the terms video frame anddigital image may be used interchangeably herein.

In addition to image data 108, the image sensor 106 may be configured tocapture phase detection (PD) data 110. Therefore, the image sensor 106may be configured to provide both image data 108 and/or PD data 110. ThePD data 110 may be used for automatic focusing (AF) operations. Forexample, the image data 108, the PD data 110 or both may be provided toan AF module 122 that determines a position of the lens 114 based on thePD data 110. This process of determining a lens position for optimalfocus is referred to as autofocus or an autofocus operation.

The electronic device 102 may include an image signal processor (ISP)120 that performs image processing operations on image data 108 and/orphase detection (PD) data 110. The image processor 120 may receive imagedata 108 and/or PD data 110 from the image sensor 106 or from the memorybuffer 116 and performs image processing.

The ISP 120 may be realized by one or more microprocessors, digitalsignal processors (DSPs), application specific integrated circuits(ASICs), field programmable gate arrays (FPGAs), or any other equivalentdiscrete or integrated logic circuitry, or a combination thereof. Insome implementations, the ISP 120 may form part of an encoder-decoder(CODEC) that encodes the image information according to a particularencoding technique or format, such as Motion Pictures Expert Group(MPEG)-2, MPEG-4, International Telecommunication Union (ITU) H.263, ITUH.264, Joint Photographic Experts Group (JPEG), Graphics InterchangeFormat (GIF), Tagged Image File Format (TIFF) or the like. The ISP 120may perform additional processing on the image information, such asimage cropping, compression, enhancement and the like.

It should be noted that the depiction of different features as units ormodules is intended to highlight different functional aspects of imageprocessing that may be performed by ISP 120, and does not necessarilyimply that such units or modules must be realized by separate hardware,software and/or firmware components. Rather, functionality associatedwith one or more units or modules may be integrated within commonhardware, software components and/or firmware components.

An image sensor 106 that is configured to capture PD data 110 may bereferred to as dual pixel technology. Each pixel may be represented bytwo sub pixel data (e.g., left and right). In an implementation, pixelsof the image sensor 106 may be divided into a left portion and a rightportion. Light rays may pass through a pair of apertures (one aperturecorresponding to the left portion and the other aperture correspondingto the right portion). After passing through the apertures, the lightmay be projected onto the image sensor 106.

The left sub pixel may measure one light profile based on where thelight is detected on the left portion of image sensor 106. The right subpixel may measure another light profile based on where the light isdetected on the right portion of image sensor 106. The PD data 110includes the left and right sub pixel data.

The difference between the two measured light profiles provides a phasedifference. When an object is in focus, the light profiles converge andthere is no phase difference. The difference between light profilesmeasured by the left and right sub pixels results in a phase difference,this phase difference may be used to perform automatic focus. Combiningthe left and right sub pixel data provides the image data 108.

The image sensor 106 may be configured to transmit the PD data 110 toone or more subsystems of the electronic device 102. For example, theimage sensor 106 may be configured to transmit the PD data 110 to theISP 120 on a data bus. In an implementation, the ISP 120 may provide thePD data 110 or PD statistics to the AF module 122 to perform automaticfocus.

The AF module 122 may check the phase difference between the leftportion and the right portion of the pixels. Based on the phasedifference, the AF module 122 may determine where the actual focus pointis. For example, the AF module 122 may determine an amount of the phasedifference. The AF module 122 may then instruct the optical system 112to move the lens 114 to a position that minimizes the phase difference.

It should be noted that the image sensor 106 may provide PD data 110 indifferent formats. Furthermore, PD data parsing to generate PDstatistics for the AF module 122 may be done in hardware via the ISP 120(if supported) or a software-based phase detection library (if the ISP120 does not support processing the PD data 110). The software-basedphase detection library is referred to herein as a PD parser.

In a first PD data format, the image sensor 106 of the electronic device102 may be configured to transmit both image data 108 and PD data 110.In this format, the image sensor 106 may provide both image data 108 anddown-sampled PD data 110 for a full field of view (FOV). The image data108 may be provided to the ISP 120 as it is and will be processed by theISP 120. This first PD data format is described in more detail inconnection with FIG. 6.

In a second PD data format, the image sensor 106 may be configured totransmit only PD data 110 from which image data 108 is obtained. In animplementation, the image sensor 106 may capture PD data 110 at twotimes (2×) the number of pixels for full FOV. The 2× PD data 110 may beprocessed by the ISP 120 or the PD parser (if the ISP 120 does notsupport processing the PD data 110). The ISP 120 or PD parser maygenerate the image data 108 by fusing the left and right PD data 110.The ISP 120 or PD parser may also generate the PD statistics that willbe used by AF module 122 to perform AF operations. This second PD dataformat is described in more detail in connection with FIG. 7.

In current approaches, PD data 110 is transmitted from the image sensor106 even when the PD data 110 is not needed for autofocus operations. Inthese approaches, when the image sensor 106 is active, the image sensor106 transmits a continuous stream of PD data 110. For example, from acamera launch to a camera exit, the image sensor 106 may capture PD data110, which is transmitted to the ISP 120 for processing.

Continuously transmitting PD data 110 from the image sensor 106increases the number of memory write operations and ISP processing(referred to as CPU utilization). Because of this requirement, the datarate from the image sensor 106 and the ISP 120 may be doubled, which inturn requires higher clocks for the image sensor 106 and/or the ISP 120.

Therefore, having an image sensor 106 provide both image data 108 aswell as PD data 110 may double the data rate for which the data istransmitted from the image sensor 106 to other circuitry (such as theISP 120). The increased data rate consumes significant amounts of powerbecause of higher ISP and/or image sensor clocks.

The systems and methods described herein reduce power consumption andimprove the CPU utilization by dynamically enabling the transmission ofPD data 110 from the image sensor 106 only when PD data 110 it isneeded. The described systems and methods do not impact image quality.Furthermore, the described systems and methods save significant power.

The AF module 122 may be configured to dynamically enable and disabletransmission of PD data 110 from the image sensor 106. With autofocus,the PD data 110 is only needed when there is a scene change. Forexample, the AF module 122 may only need to perform a lens positionsearch when a scene changes within the field of view of the opticalsystem 112. In an example, when there is motion in a scene, the AFmodule 122 may determine a lens position to achieve an optimum focus forthe scene. When there is no motion in the scene, the AF module 122converges on a lens position and autofocus is no longer performed untilanother scene change occurs. It is beneficial to disable transmission ofPD data 110 from the image sensor 106 when the AF module 122 is notactively performing autofocus.

The AF module 122 may be configured to disable transmission of PD data110 from the image sensor 106 until a scene change is detected. In anexample, when no scene change is detected, the AF module 122 may send asignal to the image sensor 106 to turn off transmission of the PD data110. For instance, the AF module 122 may send a signal to the imagesensor 106 to turn off the PD data stream to the ISP 120. The imagesensor 106 may continue to provide image data 108 while transmission ofthe PD data 110 is disabled.

It should be noted that in a dual pixel technology image sensor 106, thesame pixels may be used for capturing PD data 110 and image data 108.Irrespective of whether transmission of the PD data 110 is enabled ordisabled, the image sensor 106 may capture the PD data 110. However,when transmission of the PD data 110 is disabled, the image sensor 106may not send the captured PD data 110 on a bus to other circuitry (e.g.,the ISP 120). In an implementation, internal hardware of the imagesensor 106 that is used to send the PD data 110 may be disabled inresponse to receiving the signal from the AF module 122 to the disablePD data transmission.

The AF module 122 may be configured to enable the transmission of PDdata 110 in response to detecting a scene change. For example, when ascene change is detected, the AF module 122 may send a signal to theimage sensor 106 to turn on the transmission of PD data 110. The AFmodule 122 may then use the PD data 110 received from the image sensor106 to perform an autofocus operation. Therefore, transmission of PDdata 110 may be dynamically enabled only when PD data 110 is needed.

The electronic device 102 may be configured with a scene change detector124. The scene change detector 124 may implement one or more scenechange detection mechanisms. In an implementation, the scene changedetector 124 may determine a scene change based on movement of theelectronic device 102. In an approach, the scene change detector 124 maydetermine movement of the electronic device 102 based on angularmovement as indicated by the output of a gyroscope located on theelectronic device 102.

In another implementation, the scene change detector 124 may determine ascene change based on automatic exposure control (AEC) exposureinformation. For example, an AEC module (not shown) may provide exposureinformation to the scene change detector 124. When the AEC exposureinformation changes within a threshold amount from one image frame toanother, this may indicate a scene change.

In yet another implementation, the scene change detector 124 maydetermine a scene change based on a sum of absolute differences (SAD).In image processing, the SAD is a measure of the similarity betweenimages or portions of image blocks. The SAD may be determined by takingthe absolute difference between each pixel in an original block and eachcorresponding pixel in a subsequent block. If the SAD is above a certainthreshold, then this may indicate a scene change.

In yet another implementation, the scene change detector 124 maydetermine a scene change based on a digital image correlation. Thedigital image correlation may be performed to detect changes from oneimage frame to another image frame. If the digital image correlation isabove a certain threshold, then this may indicate a scene change. Itshould be noted that other mechanisms may be utilized by the scenechange detector 124 to determine a scene change.

When detecting a scene change, the scene change detector 124 may send anindication to the AF module 122 that the scene has changed. The AFmodule 122 may enable the transmission of PD data 110 from the imagesensor 106 in response to detecting the scene change. For example, theAF module 122 may send a PD data enable signal to the image sensor 106.

Upon enabling transmission of the PD data 110 from the image sensor 106,the AF module 122 may perform an autofocus operation using the PD data110. In an implementation, the AF module 122 may receive PD statisticsfrom the ISP 120 and/or a PD parser. The AF module 122 may analyze thePD data 110 (or the PD statistics) to determine a lens position. Thisoperation may be referred to as an AF search or lens position search.The AF module 122 may provide the lens position to the optical system112, which moves the lens 114 into the peak lens position.

At this point, the PD data 110 is no longer needed for autofocus untilthere is another scene change. The AF module 122 may disabletransmission of PD data 110 from the image sensor 106 after performingthe autofocus operation.

In an implementation, the AF module 122 may be configured to perform afine search to determine a final lens position after disablingtransmission of the PD data 110 from the image sensor 106. In this case,the AF module 122 may perform a fine search for accurate peak lensposition. The AF module 122 may determine a final lens position usingimage data 108 from the image sensor 106 without using the PD data 110.

In another implementation, the AF module 122 may check the PD data 110and based on that will move the lens 114 to a focus position. This focusposition may be approximately accurate. To get a very accurate position,the AF module 122 may perform the fine search using contrast AF dataprovided by the ISP 120. Generally, a high pass filter may run for animage pixel in the ISP 120 to determine the contrast AF data. Thecontrast AF data may be gathered at different lens positions. The lensposition where the contrast AF data is maximized is the best focusposition. The lens 114 may be moved to that lens position.

It should also be noted that enabling and disabling transmission of thePD data 110 from the image sensor 106 may have only a one frame delay.This delay is negligible in normal light and frame rates (e.g., 30frames per second (fps)).

In the case of the first PD data format described above, the ISP 120 mayreceive image data 108 with or without PD data 110. The ISP 120 mayreceive the image data 108 and the PD data 110 from the image sensor 106when transmission of the PD data 110 is enabled. For example, when ascene change is detected and the AF module 122 enables transmission ofthe PD data 110, the ISP 120 may receive both the image data 108 and thePD data 110 from the image sensor 106. When transmission of the PD data110 is disabled, the ISP 120 may receive the image data 108 from theimage sensor 106 without PD data 110. For example, when a scene changeis not detected and the AF module 122 disables transmission of the PDdata 110, then the ISP 120 may receive only the image data 108 from theimage sensor 106.

In the case of the second PD data format described above, the ISP 120may receive PD data 110 106 from the image sensor 106 when transmissionof the PD data 110 is enabled. For example, when a scene change isdetected and the AF module 122 enables transmission of the PD data 110,the ISP 120 may receive 2× PD data 110 from the image sensor 106. Whentransmission of the PD data 110 is disabled, the ISP 120 may receiveimage data 108 from the image sensor 106 without PD data 110. Forexample, when a scene change is not detected and the AF module 122disables transmission of the PD data 110, then the image sensor 106 mayconvert the PD data 110 to image data 108. The image sensor 106 may thensend only the image data 108 to the ISP 120.

The systems and methods described herein provide significant powersavings without reducing image quality. By disabling transmission of thePD data 110 from the image sensor 106, the ISP clock, image sensor clockand data transfer clock are reduced. Additionally, by disabling PD datatransmission, power consumption may be decreased due to reduced memorywrites. Furthermore, the memory buffer 116 may be saved by almost halfwhen PD data transmission is disabled, thus making more memory availablefor other operations.

FIG. 2 is a flow diagram illustrating a method 200 for dynamicallyenabling and disabling transmission of PD data 110 from an image sensor106. The method 200 may be implemented by an electronic device 102. Inan implementation, the electronic device 102 may be configured with animage sensor 106, an AF module 122 and an ISP 120.

The electronic device 102 may capture 202 PD data 110 for automaticfocusing by the image sensor 106. In an implementation, the image sensor106 may be configured to capture image data 108 and PD data 110. Inanother implementation, the image sensor 106 may be configured tocapture PD data 110 from which image data 108 is generated. The imagesensor 106 may be configured to provide the PD data 110 to the ISP 120or a PD parser. The ISP 120 or PD parser may be configured to providethe PD data 110 to the AF module 122.

The electronic device 102 may dynamically enable or disable 204transmission of the PD data 110 from the image sensor 106. The AF module122 may be configured to disable transmission of the PD data 110 fromthe image sensor 106 until detecting a scene change. In an example, theAF module 122 may send a signal to the image sensor 106 to turn offtransmission of the PD data 110 to the ISP 120.

The AF module 122 may be configured to enable transmission of the PDdata 110 from the image sensor 106 in response to detecting a scenechange. For example, the AF module 122 may send a signal to the imagesensor 106 to turn on transmission of the PD data 110. In animplementation, the AF module 122 may analyze the PD data 110 todetermine a lens position after enabling transmission of the PD data 110from the image sensor 106 in response to detecting a scene change. TheAF module 122 may subsequently disable transmission of the PD data 110from the image sensor 106.

The electronic device 102 may detect a scene change based on one or morescene detection mechanisms. These scene detection mechanisms may includea gyroscope output (e.g., angular movement), automatic exposure control(AEC) exposure information, a sum of absolute differences, digital imagecorrelation or a combination thereof.

In an implementation corresponding to the first PD data format, the ISP120 may be configured to receive the image data 108 and the PD data 110from the image sensor 106 when transmission of the PD data 110 isenabled. The ISP 120 may be configured to receive the image data 108from the image sensor 106 without PD data 110 when transmission of thePD data 110 is not enabled.

In an implementation corresponding to the second PD data format, the ISP120 may be configured to receive PD data 110 from the image sensor 106when transmission of the PD data 110 from the image sensor 106 isenabled. In this case, the ISP 120 may generate image data 108 bycombining the PD data 110. The ISP 120 may be configured to receiveimage data 108 from the image sensor 106 without PD data 110 whentransmission of the PD data 110 from the image sensor 106 is disabled.In this case, the image sensor 106 may combine the PD data 110 togenerate the image data 108, which is sent to the ISP 120.

FIG. 3 is a block diagram illustrating another configuration of anelectronic device 302 configured to dynamically enable and disabletransmission of PD data 310 from an image sensor 306. The electronicdevice 302 may be configured with an image sensor 306. The image sensor306 may capture image data 308 and/or PD data 310. The image sensor 306may provide the image data 308 and/or PD data 310 to an ISP 320.

The electronic device 302 may be configured with one or more imageenhancement modules 326 to perform various image enhancement operations.For example, the electronic device 302 may be configured with an autowhite balance (AWB) module and/or an automatic exposure control (AEC)module. The image enhancement module 326 may provide RGB gains and/or acorrelated color temperature (CCT) 328 to the ISP 320. The imageenhancement module 326 may also provide exposure settings 330 to theimage sensor 306. In an implementation, the AEC may be configured toprovide exposure information to a scene change detector 324.

The AF module 322 may be configured to enable or disable transmission ofthe PD data 310 from the image sensor 306. The AF module 322 may send aPD enable/disable signal 332 to the image sensor 306 to either enable(i.e., turn on) or disable (i.e., turn off) transmission of the PD data310 to the ISP 320.

An autofocus search for a lens position 334 is only needed when a scenechanges. Therefore, the AF module 322 may enable transmission of the PDdata 310 from the image sensor 306 when a scene change is detected. TheAF module 322 may perform an autofocus search to determine the lensposition 334 and may subsequently disable transmission of the PD data310 from the image sensor 306. Then, the AF module 322 may dynamicallyre-enable transmission of the PD data 310 from the image sensor 306 upondetecting another scene change.

The electronic device 302 may be configured with a scene change detector324 that detects when a scene changes. The scene change detector 324 maydetect a scene change based on one or more of a gyroscope output (e.g.,angular movement), automatic exposure control (AEC) exposureinformation, a sum of absolute differences or digital image correlation.

The scene change detector 324 may notify the AF module 322 of a scenechange. In response to detecting the scene change, the AF module 322 maysend a PD data enable signal 332 to the image sensor 306. The imagesensor 306 may then send the PD data 310 to the ISP 320. The ISP 320 maysend the PD data 310 to the AF module 322.

Upon receiving the PD data 310, the AF module 322 may analyze the PDdata 310 to determine a lens position 334 to move the lens 114 to a peakposition for correct focus. The AF module 322 may send the lens position334 to the optical system 112 of image sensor 306. The lens 114 may befocused according to the lens position 334. For example, anelectromechanical system may adjust the focus of the optical system 112according to the lens position 334 determined by the AF module 322.

Upon finishing the AF search and sending the lens position 334, the AFmodule 322 may disable transmission of the PD data 310 from the imagesensor 306. For example, the AF module 322 may send a PD data disablesignal 332 to the image sensor 306. The image sensor 306 may stoptransmitting the PD data 310 in response to the PD data disable signal332. However, the image sensor 306 may continue to provide image data308 to the ISP 320 while transmission of the PD data 310 is disabled.Thus, the electronic device 302 may optimize power consumption bydisabling transmission of the PD data 310 when it is not needed.

In an implementation, the AF module 322 may perform a fine search foraccurate peak position of the lens position 334 after disablingtransmission of the PD data 310. The AF module 322 may determine a finallens position 334 using image data 308 from the image sensor 306 withoutthe PD data 310.

To summarize, the scene change detector 324 may trigger the AF search.Whenever a scene change is detected, transmission of the PD data 310from the image sensor 306 may be enabled. Based on the PD data 310, theoptical system 112 may move the lens to the lens position 334 determinedby the AF module 322. Transmission of the PD data 310 from the imagesensor 306 may then be disabled. The AF module 322 may perform a finalsearch for the lens position 334. The electronic device 302 may thenperform digital image operations without the PD data 310.

FIG. 4 is a flow diagram illustrating another configuration of a method400 for dynamically enabling and disabling transmission of PD data 110.The method 400 may be implemented by an electronic device 102. In animplementation, the electronic device 102 may be configured with animage sensor 106, an AF module 122, a scene change detector 124 and anISP 120.

In a first PD data format, the image sensor 106 may be configured tocapture image data 108 and PD data 110. In a second PD data format, theimage sensor 106 may be configured to capture 2× PD data 110 from whichimage data 108 and PD statistics are obtained.

The electronic device 102 may capture 402 one or more image frames. Asused herein, a frame is an individual image. The image sensor 106 maycapture image data 108 and/or PD data 110 for a number of image frames.In an implementation, the image sensor 106 may capture a certain numberof image frames at a certain rate (e.g., 30 fps).

The electronic device 102 may detect 404 a scene change. In animplementation, a scene change detector 124 may detect a scene changebased on movement of the electronic device 102 (e.g., angular movementas detected by a gyroscope). In another implementation, the scene changedetector 124 may detect a scene change based on changes in the imageframes. For example, the scene change detector 124 may detect a scenechange based on a sum of absolute differences (SAD), AEC exposureinformation and/or digital image correlation. In yet anotherimplementation, the scene change detector 124 may detect a scene changebased on a combination of these or other scene change detectionmechanisms.

The electronic device 102 may enable 406 transmission of PD data 110from the image sensor 106. For example, the AF module 122 may send a PDdata enable signal 332 to the image sensor 106. Upon receiving the PDdata enable signal 332, the image sensor 106 may send PD data 110. ThePD data 110 may be received by the ISP 120, which sends the PD data 110(or PD statistics) to the AF module 122.

The electronic device 102 may analyze 408 the PD data 110 and move alens 114 to peak lens position 334. For example, the AF module 122 maydetermine a lens position 334 for optimal focus based on the PD data110. The AF module 122 may send the lens position 334 to the opticalsystem 112 of image sensor 106. The lens 114 may be focused (e.g., movedor positioned) according to the lens position 334.

The electronic device 102 may disable 410 transmission of the PD data110 from the image sensor 106. Upon performing the autofocus search forthe lens position 334, the AF module 122 may send a PD data disablesignal 332 to the image sensor 106. The image sensor 106 may disable(i.e., stop) the transmission of the PD data 110 in response to the PDdata disable signal 332.

The electronic device 102 may perform 412 a fine search for accuratepeak position of the lens 114. After disabling transmission of the PDdata 110 from the image sensor 106, the AF module 322 may continue todetermine a final lens position 334 using image data 108 from the imagesensor 106 without the PD data 110.

FIG. 5 is a flow diagram illustrating yet another configuration of amethod 500 for dynamically enabling and disabling transmission of PDdata 110. The method 500 may be implemented by an electronic device 102.In an implementation, the electronic device 102 may be configured withan image sensor 106, an AF module 122 and an ISP 120.

In a first PD data format, the image sensor 106 may be configured tosend image data 108 and down-sampled PD data 110 to an ISP 120. In asecond PD data format, the image sensor 106 may be configured to send 2×PD data 110 from which image data 108 and PD statistics are obtained.

The electronic device 102 may enable 502 a camera 104. For example, acamera application may be launched (on a smartphone, for instance). Inanother example, a digital camera may be turned on or placed in anactive mode to capture a digital image.

The electronic device 102 may perform 504 autofocus using PD data 110from the image sensor 106. When the camera 104 is first launched, theimage sensor 106 may capture PD data 110. In this case, the scene is newto the electronic device 102. The AF module 122 may perform an initialautofocus using the PD data 110 or PD statistics. The AF module 122 mayprovide the optical system 112 with a lens position 334.

The electronic device 102 may disable 506 transmission of the PD data110 from the image sensor 106. After completing the autofocus operation,the AF module 122 no longer needs PD data 110 unless the scene changes.To conserve energy, the electronic device 102 may disable 506transmission of the PD data 110 from the image sensor 106. In animplementation, the AF module 122 may send a PD data disable signal 332to the image sensor 106. The image sensor 106 may continue to provideimage data 108 to the ISP 120.

The electronic device 102 may monitor 508 for a scene change. Whilemonitoring 508 for a scene change, the electronic device 102 maydetermine whether one or more criteria have been met to indicate a scenechange. In an implementation, the electronic device 102 may detect ascene change based on movement of the electronic device 102 (e.g.,angular movement as detected by a gyroscope). In another implementation,the electronic device 102 may detect a scene change based on changes inthe image frames. For example, the electronic device 102 may detect ascene change based on a sum of absolute differences (SAD), AEC exposureinformation and/or digital image correlation. In yet anotherimplementation, the electronic device 102 may detect a scene changebased on a combination of these or other scene change detectionmechanisms.

The electronic device 102 may determine 510 whether a scene change hasbeen detected. If the one or more scene change criteria have not beenmet, then the electronic device 102 may continue to monitor 508 for ascene change. In this case, the image sensor 106 may continue to provideimage data 108 to the ISP 120 without PD data 110.

If the electronic device 102 determines 510 that a scene change isdetected, then the electronic device 102 may enable 512 transmission ofthe PD data 110 from the image sensor 106. For example, the AF module122 may send a PD data enable signal 332 to the image sensor 106. Uponreceiving the PD data enable signal 332, the image sensor 106 may sendthe PD data 110 in addition to the image data 108. The image data 108and PD data 110 may be received by the ISP 120, which sends the PD data110 to the AF module 122.

The electronic device 102 may analyze 514 the PD data 110 to determine alens position 334. This may be accomplished as described in connectionwith FIG. 4.

The electronic device 102 may disable 516 transmission of the PD data110 from the image sensor 106. Upon moving the lens 114 to the targetposition based on the phase detection data 110, the AF module 122 maysend a PD data disable signal 332 to the image sensor 106. The imagesensor 106 may disable (i.e., stop) transmission of the PD data 110 inresponse to the PD data disable signal 332.

The electronic device 102 may perform 518 a fine search for accuratepeak position of the lens 114. After disabling transmission of the PDdata 110 from the image sensor 106, the AF module 322 may continue todetermine a final lens position 334 using image data 108 from the imagesensor 106 without the PD data 110.

The electronic device 102 may continue to monitor 508 for a scenechange. If the electronic device 102 detects 510 another scene change,then the electronic device 102 may re-enable 512 transmission of the PDdata 110 from the image sensor 106 to perform another autofocusoperation. Otherwise, the electronic device 102 may continue imageprocessing operations using captured image data 108 without the PD data110.

FIG. 6 is a block diagram illustrating another configuration of anelectronic device 602 configured to dynamically enable and disabletransmission of PD data 610. The electronic device 602 may be configuredwith an image sensor 606. The image sensor 606 may capture image data608 and PD data 610. The image sensor 606 may provide the image data 608and PD data 610 to an ISP 620. This is an example of the first PD dataformat described in connection with FIG. 1.

In this first PD data format, the image sensor 606 of the electronicdevice 602 may be configured to capture both image data 608 and PD data610. In this format, the image sensor 606 may provide both image data608 and down-sampled PD data 610 for a full field of view (FOV). Theimage data 608 may be provided to the ISP 620 as it is and will beprocessed by the ISP 620. In an example of the first PD data format,image data 608 may be 10 megapixels (MP) and the down-sampled PD data610 a may be 2.5 MP.

The ISP 620 may send a contrast AF signal 640 based on the image data608. The ISP 620 may provide the contrast AF signal 640 by running ahigh pass filter on image data 608, which is used to do a fine searchfor the lens position 634.

If supported by the ISP 620, the image sensor 606 may send thedown-sampled PD data 610 a to the ISP 620. The ISP 620 may process thePD data 610 a to generate PD statistics (stats) 638 a, which areprovided to the AF module 622. The PD statistics 638 a may be generatedby parsing the PD data 610 a.

If the ISP 620 does not support PD data processing, the image sensor 606may send the down-sampled PD data 610 b to a PD parser 636 to generatethe PD statistics 638 b for the AF module 622. The PD statistics 638 bmay be generated by parsing the PD data 610 b.

The electronic device 602 may be configured with one or more imageenhancement modules 626 to perform various image enhancement operations.For example, the electronic device 602 may be configured with an autowhite balance (AWB) module and/or an automatic exposure control (AEC)module. The image enhancement module 626 may provide white balancesettings to the ISP 642. The image enhancement module 626 may alsoprovide exposure settings 630 to the image sensor 606. In animplementation, the AEC may be configured to provide exposureinformation to a scene change detector 624.

The AF module 622 may be configured to enable or disable transmission ofthe PD data 610 from the image sensor 606. The AF module 622 may send aPD enable/disable signal 632 to the image sensor 606 to either enable(i.e., start) or disable (i.e., stop) transmission of the PD data 610 tothe ISP 620 or PD parser 636.

An autofocus search for a lens position 634 is only needed when a scenechanges. Therefore, the AF module 622 may enable transmission of the PDdata 610 from the image sensor 606 when a scene change is detected. TheAF module 622 may perform an autofocus search to determine the lensposition 634 and may subsequently disable transmission of the PD data610 from the image sensor 606. Then, the AF module 622 may dynamicallyre-enable transmission of the PD data 610 from the image sensor 606 upondetecting another scene change.

The electronic device 602 may be configured with a scene change detector624 that detects when a scene changes. The scene change detector 624 maydetect a scene change based on one or more of a gyroscope output (e.g.,angular movement), automatic exposure control (AEC) exposureinformation, a sum of absolute differences or digital image correlation.

The scene change detector 624 may notify the AF module 622 of a scenechange. In response to detecting the scene change, the AF module 622 maysend a PD data enable signal 632 to the image sensor 606. The imagesensor 606 may then send the PD data 610 to the ISP 620 or the PD parser636. The ISP 620 or the PD parser 636 may send the PD statistics 638 tothe AF module 622.

Upon receiving the PD statistics 638, the AF module 622 may analyze thePD statistics 638 to determine a lens position 634 to move the lens 114to a peak position for correct focus. The AF module 622 may send thelens position 634 to the optical system 112 of image sensor 606. Thelens 114 may be focused according to the lens position 634. For example,an electromechanical system may adjust the focus of the optical system112 according to the lens position 634 determined by the AF module 622.

Upon finishing the AF search and sending the lens position 634, the AFmodule 622 may disable transmission of the PD data 610 from the imagesensor 606. For example, the AF module 622 may send a PD data disablesignal 632 to the image sensor 606. The image sensor 606 may stoptransmitting the PD data 610 in response to the PD data disable signal632. However, the image sensor 606 may continue to provide image data608 to the ISP 620 while transmission of the PD data 610 is disabled.Thus, the electronic device 602 may optimize power consumption bydisabling transmission of the PD data 610 when it is not needed.

In an implementation, the AF module 622 may perform a fine search foraccurate peak position of the lens position 634 after disablingtransmission of the PD data 610 from the image sensor 606. The AF module622 may determine a final lens position 634 using image data 608 fromthe image sensor 606 without the PD data 610.

To summarize, the scene change detector 624 may trigger the AF search.Whenever a scene change is detected, transmission of the PD data 610from the image sensor 606 may be enabled. Based on the PD data 610, theoptical system 112 may move the lens to the lens position 634 determinedby the AF module 622. Transmission of the PD data 610 from the imagesensor 606 may be disabled. The AF module 622 may perform a final searchfor the lens position 634. The electronic device 602 may then performdigital image operations without the PD data 610.

FIG. 7 is a block diagram illustrating yet another configuration of anelectronic device 702 configured to dynamically enable and disabletransmission of PD data 710. The electronic device 702 may be configuredwith an image sensor 706. The image sensor 706 may capture PD data 710.This is an example of the second PD data format described in connectionwith FIG. 1.

The image sensor 706 may be configured to send PD data 710, from whichimage data 708 is obtained. For example, the image sensor 706 maycapture PD data 710 at two times (2×) the number of pixels for full FOV.The 2× PD data 710 may include left and right PD data 710. Image data708 may be generated from the PD data 710 by merging the left and rightPD data 710.

In an example of the second PD data format, the image resolution of theimage data 708 may be 10 megapixels (MP). In this case, the PD data 710may be 20 MP, with 10 MP for the left PD data 710 and 10 MP for theright PD data 710. Internally, the image sensor 706 may have a 20megapixel sensor. Each pixel may be divided into left and right subpixels as described in connection with FIG. 1. If transmission of PDdata 710 is enabled, the image sensor 706 may send the 20 MP PD data 710to either the ISP 720 or a PD parser 736. Parsing may be performed toretrieve the image data 708 and PD statistics 738. For example, the ISP720 may process the 20 MP of PD data 710 a to generate the 10 MP imagedata 708 and PD statistics 738 a.

When transmission of PD data 710 is disabled, then the image sensor 706may internally combine the PD data 710 from the left and right subpixels. The image sensor 706 may then send the 10 MP image data 708 a onthe same data transfer line to the ISP 720. In this case, no parsing isneeded.

If the ISP 720 supports processing of the PD data 710, the image sensor706 may send the PD data 710 a to the ISP 720. The ISP 720 may generateimage data 708 by fusing the left and right PD data 710 a. The ISP 720may send a contrast AF signal 740 based on the image data 708. The ISP720 may also generate the PD statistics 738 a that will be used by AFmodule 722 to perform AF operations. The PD statistics 738 a may begenerated by parsing the PD data 710 a.

If the ISP 720 does not support PD data processing, the image sensor 706may send the PD data 710 b to a PD parser 736. The PD parser 736 maygenerate image data 708 b by fusing the left and right PD data 710 b.The PD parser 736 may send the image data 708 b to the ISP 720. The PDparser 736 may also generate the PD statistics 738 b for the AF module722. The PD statistics 738 b may be generated by parsing the PD data 710b.

The electronic device 702 may be configured with one or more imageenhancement modules 726 to perform various image enhancement operations.For example, the electronic device 702 may be configured with an autowhite balance (AWB) module and/or an automatic exposure control (AEC)module. The image enhancement module 726 may provide white balancesettings to the ISP 742. The image enhancement module 726 may alsoprovide exposure settings 730 to the image sensor 706. In animplementation, the AEC may be configured to provide exposureinformation to a scene change detector 724.

The AF module 722 may be configured to enable or disable transmission ofthe PD data 710 from the image sensor 706. The AF module 722 may send aPD enable/disable signal 732 to the image sensor 706 to either enable ordisable transmission of the PD data 710.

In this second PD data format, when transmission of the PD data 710 isenabled, the image sensor 706 may send the 2× PD data 710 to either theISP 720 or the PD parser 736. In other words, when transmission of PDdata 710 is enabled, the image sensor 706 may send both the left andright PD data 710 to the ISP 720 or PD parser 736 for processing.

When transmission of the PD data 710 is disabled, the image sensor 706may generate the image data 708 a from the left and right PD data 710.However, the image sensor 706 may only send the image data 708 a to theISP 720 without sending the 2× PD data 710. In other words, whentransmission of PD data 710 is disabled, the image sensor 706 may sendonly image data 708 a to the ISP 720. When transmission of the PD data710 is disabled in this fashion, the image sensor 706 may send imagedata 708 a for full FOV without the 2× PD data 710, which willsignificantly reduce the power consumption of the electronic device 702.

An autofocus search for a lens position 734 is only needed when a scenechanges. Therefore, the AF module 722 may enable transmission of the PDdata 710 from the image sensor 706 when a scene change is detected. TheAF module 722 may perform an autofocus search to determine the lensposition 734 and may subsequently disable transmission of the PD data710 from the image sensor 706. Then, the AF module 722 may dynamicallyre-enable transmission of the PD data 710 from the image sensor 706 upondetecting another scene change.

The electronic device 702 may be configured with a scene change detector724 that detects when a scene changes. The scene change detector 724 maydetect a scene change based on one or more of a gyroscope output (e.g.,angular movement), automatic exposure control (AEC) exposureinformation, or a sum of absolute differences or digital imagecorrelation.

The scene change detector 724 may notify the AF module 722 of a scenechange. In response to detecting the scene change, the AF module 722 maysend a PD data enable signal 732 to the image sensor 706. The imagesensor 706 may then transmit the PD data 710 (e.g., the full 2× PD data710) to the ISP 720 or the PD parser 736. The ISP 720 or the PD parser736 may send the PD statistics 738 to the AF module 722.

Upon receiving the PD statistics 738, the AF module 722 may analyze thePD statistics 738 to determine a lens position 734 to move the lens 114to a peak position for correct focus. The AF module 722 may send thelens position 734 to the optical system 112 of image sensor 706. Thelens 114 may be focused according to the lens position 734. For example,an electromechanical system may adjust the focus of the optical system112 according to the lens position 734 determined by the AF module 722.

Upon finishing the AF search and sending the lens position 734, the AFmodule 722 may disable transmission of the PD data 710 from the imagesensor 706. For example, the AF module 722 may send a PD data disablesignal 732 to the image sensor 706. The image sensor 706 may stoptransmitting PD data 710 in response to the PD data disable signal 732.However, the image sensor 706 may continue to provide image data (lx)708 to the ISP 720 while transmission of the PD data 710 is disabled.Thus, the electronic device 702 may optimize power consumption bydisabling transmission of the PD data 710 when it is not needed.

In an implementation, the AF module 722 may perform a fine search foraccurate peak position of the lens position 734 after disablingtransmission of the PD data 710. The AF module 722 may determine a finallens position 734 using image data 708 from the image sensor 706 withoutthe PD data 710.

FIG. 8 illustrates certain components that may be included within anelectronic device 802. The electronic device 802 described in connectionwith FIG. 8 may be an example of and/or may be implemented in accordancewith the electronic device 102 described in connection with FIG. 1.

The electronic device 802 includes a processor 803. The processor 803may be a general purpose single- or multi-core microprocessor (e.g., anAdvanced RISC (Reduced Instruction Set Computer) Machine (ARM)), aspecial purpose microprocessor (e.g., a digital signal processor (DSP)),a microcontroller, a programmable gate array, etc. The processor 803 maybe referred to as a central processing unit (CPU). Although just asingle processor 803 is shown in the electronic device 802 of FIG. 8, inan alternative configuration, a combination of processors (e.g., an ARMand DSP) could be used.

The electronic device 802 also includes memory 805 in electroniccommunication with the processor 803 (i.e., the processor can readinformation from and/or write information to the memory). The memory 805may be any electronic component capable of storing electronicinformation. The memory 805 may be configured as Random Access Memory(RAM), Read-Only Memory (ROM), magnetic disk storage media, opticalstorage media, flash memory devices in RAM, on-board memory includedwith the processor, Erasable Programmable Read-Only Memory (EPROM),Electrically Erasable Programmable Read-Only Memory (EEPROM), registersand so forth, including combinations thereof.

Data 807 a and instructions 809 a may be stored in the memory 805. Theinstructions 809 a may include one or more programs, routines,sub-routines, functions, procedures, code, etc. The instructions 809 amay include a single computer-readable statement or manycomputer-readable statements. The instructions 809 a may be executableby the processor 803 to implement the methods disclosed herein.Executing the instructions 809 a may involve the use of the data 807 athat is stored in the memory 805. When the processor 803 executes theinstructions 809, various portions of the instructions 809 b may beloaded onto the processor 803, and various pieces of data 807 b may beloaded onto the processor 803.

The electronic device 802 may also include a transmitter 811 and areceiver 813 to allow transmission and reception of signals to and fromthe electronic device 802 via one or more antennas 817 a-b. Thetransmitter 811 and receiver 813 may be collectively referred to as atransceiver 815. As used herein, a “transceiver” is synonymous with aradio. The electronic device 802 may also include (not shown) multipletransmitters, multiple antennas, multiple receivers and/or multipletransceivers.

The electronic device 802 may include a digital signal processor (DSP)821. The electronic device 802 may also include a communicationsinterface 827. The communications interface 827 may allow a user tointeract with the electronic device 802.

The various components of the electronic device 802 may be coupledtogether by one or more buses, which may include a power bus, a controlsignal bus, a status signal bus, a data bus, etc. For the sake ofclarity, the various buses are illustrated in FIG. 8 as a bus system819.

In the above description, reference numbers have sometimes been used inconnection with various terms. Where a term is used in connection with areference number, this may be meant to refer to a specific element thatis shown in one or more of the Figures. Where a term is used without areference number, this may be meant to refer generally to the termwithout limitation to any particular Figure.

The term “determining” encompasses a wide variety of actions and,therefore, “determining” can include calculating, computing, processing,deriving, investigating, looking up (e.g., looking up in a table, adatabase or another data structure), ascertaining and the like. Also,“determining” can include receiving (e.g., receiving information),accessing (e.g., accessing data in a memory) and the like. Also,“determining” can include resolving, selecting, choosing, establishingand the like.

The phrase “based on” does not mean “based only on,” unless expresslyspecified otherwise. In other words, the phrase “based on” describesboth “based only on” and “based at least on.”

It should be noted that one or more of the features, functions,procedures, components, elements, structures, etc., described inconnection with any one of the configurations described herein may becombined with one or more of the functions, procedures, components,elements, structures, etc., described in connection with any of theother configurations described herein, where compatible. In other words,any compatible combination of the functions, procedures, components,elements, etc., described herein may be implemented in accordance withthe systems and methods disclosed herein.

The functions described herein may be stored as one or more instructionson a processor-readable or computer-readable medium. The term“computer-readable medium” refers to any available medium that can beaccessed by a computer or processor. By way of example, and notlimitation, such a medium may comprise Random-Access Memory (RAM),Read-Only Memory (ROM), Electrically Erasable Programmable Read-OnlyMemory (EEPROM), flash memory, Compact Disc Read-Only Memory (CD-ROM) orother optical disk storage, magnetic disk storage or other magneticstorage devices, or any other medium that can be used to store desiredprogram code in the form of instructions or data structures and that canbe accessed by a computer. Disk and disc, as used herein, includescompact disc (CD), laser disc, optical disc, digital versatile disc(DVD), floppy disk and Blu-ray® disc, where disks usually reproduce datamagnetically, while discs reproduce data optically with lasers. Itshould be noted that a computer-readable medium may be tangible andnon-transitory. The term “computer-program product” refers to acomputing device or processor in combination with code or instructions(e.g., a “program”) that may be executed, processed or computed by thecomputing device or processor. As used herein, the term “code” may referto software, instructions, code or data that is/are executable by acomputing device or processor.

Software or instructions may also be transmitted over a transmissionmedium. For example, if the software is transmitted from a website,server or other remote source using a coaxial cable, fiber optic cable,twisted pair, digital subscriber line (DSL) or wireless technologiessuch as infrared, radio and microwave, then the coaxial cable, fiberoptic cable, twisted pair, DSL or wireless technologies such asinfrared, radio and microwave are included in the definition oftransmission medium.

The methods disclosed herein comprise one or more steps or actions forachieving the described method. The method steps and/or actions may beinterchanged with one another without departing from the scope of theclaims. In other words, unless a specific order of steps or actions isrequired for proper operation of the method that is being described, theorder and/or use of specific steps and/or actions may be modifiedwithout departing from the scope of the claims.

It is to be understood that the claims are not limited to the preciseconfiguration and components illustrated above. Various modifications,changes and variations may be made in the arrangement, operation anddetails of the systems, methods and apparatus described herein withoutdeparting from the scope of the claims.

What is claimed is:
 1. An electronic device, comprising: an image sensorthat is configured to capture phase detection data for automaticfocusing; and an automatic focusing module that is configured todynamically enable or disable transmission of the phase detection datafrom the image sensor.
 2. The electronic device of claim 1, wherein theautomatic focusing module is configured to enable transmission of thephase detection data from the image sensor in response to detecting ascene change.
 3. The electronic device of claim 2, wherein the automaticfocusing module is configured to detect a scene change based on one ormore of a gyroscope output, automatic exposure control (AEC) exposureinformation, a sum of absolute differences or digital image correlation.4. The electronic device of claim 1, wherein the automatic focusingmodule is configured to disable transmission of the phase detection datafrom the image sensor until detecting a scene change.
 5. The electronicdevice of claim 1, wherein the automatic focusing module is configuredto: analyze the phase detection data to determine a lens position afterenabling transmission of the phase detection data from the image sensorin response to detecting a scene change; and subsequently disabletransmission of the phase detection data from the image sensor.
 6. Theelectronic device of claim 5, wherein the automatic focusing module isfurther configured to perform a fine search to determine a final lensposition after disabling transmission of the phase detection data fromthe image sensor.
 7. The electronic device of claim 6, wherein theautomatic focusing module is configured to perform the fine search todetermine a final lens position based on image data from the imagesensor.
 8. The electronic device of claim 1, further comprising an imagesignal processor that is configured to: receive image data and the phasedetection data from the image sensor when transmission of the phasedetection data from the image sensor is enabled; and receive image datafrom the image sensor when transmission of the phase detection data fromthe image sensor is disabled.
 9. The electronic device of claim 1,further comprising an image signal processor that is configured to:receive phase detection data from the image sensor when transmission ofthe phase detection data from the image sensor is enabled; and receiveimage data from the image sensor when transmission of the phasedetection data from the image sensor is disabled.
 10. A method,comprising: capturing, by an image sensor, phase detection data forautomatic focusing; and dynamically enabling or disabling, by anautomatic focusing module, transmission of the phase detection data fromthe image sensor.
 11. The method of claim 10, wherein dynamicallyenabling transmission of the phase detection data from the image sensorcomprises: enabling transmission of the phase detection data from theimage sensor in response to detecting a scene change.
 12. The method ofclaim 10, wherein detecting the scene change is based on one or more ofa gyroscope output, automatic exposure control (AEC) exposureinformation or a sum of absolute differences.
 13. The method of claim10, further comprising disabling, by the automatic focusing module,transmission of the phase detection data from the image sensor untildetecting a scene change.
 14. The method of claim 10, furthercomprising: analyzing the phase detection data to determine a lensposition after enabling transmission of the phase detection data fromthe image sensor in response to detecting a scene change; andsubsequently disabling transmission of the phase detection data from theimage sensor.
 15. The method of claim 14, further comprising performinga fine search to determine a final lens position after disablingtransmission of the phase detection data from the image sensor.
 16. Themethod of claim 15, wherein performing the fine search to determine afinal lens position is based on image data from the image sensor withoutthe phase detection data.
 17. The method of claim 10, furthercomprising: receiving, at an image signal processor, image data and thephase detection data from the image sensor when transmission of thephase detection data from the image sensor is enabled; and receiving, atthe image signal processor, image data from the image sensor whentransmission of the phase detection data from the image sensor isdisabled.
 18. The method of claim 10, further comprising: receiving, atan image signal processor, phase detection data from the image sensorwhen transmission of the phase detection data from the image sensor isenabled; and receiving, at the image signal processor, image data fromthe image sensor when transmission of the phase detection data from theimage sensor is disabled.
 19. An apparatus, comprising: means forcapturing, by an image sensor, phase detection data for automaticfocusing; and means for dynamically enabling or disabling, by anautomatic focusing module, transmission of the phase detection data fromthe image sensor.
 20. The apparatus of claim 19, wherein the means fordynamically enabling transmission of the phase detection data from theimage sensor comprise: means for enabling transmission of the phasedetection data from the image sensor in response to detecting a scenechange.
 21. The apparatus of claim 20, wherein detecting the scenechange is based on one or more of a gyroscope output, automatic exposurecontrol (AEC) exposure information or a sum of absolute differences. 22.The apparatus of claim 19, further comprising means for disablingtransmission of the phase detection data from the image sensor untildetecting a scene change.
 23. The apparatus of claim 19, furthercomprising: means for analyzing the phase detection data to determine alens position after enabling transmission of the phase detection datafrom the image sensor in response to detecting a scene change; and meansfor subsequently disabling transmission of the phase detection data fromthe image sensor.
 24. The apparatus of claim 23, further comprisingmeans for performing a fine search to determine a final lens positionafter disabling transmission of the phase detection data from the imagesensor.
 25. A non-transitory tangible computer readable medium storingcomputer executable code, comprising: code for causing an image sensorto capture phase detection data for automatic focusing; and code forcausing an automatic focusing module to dynamically enable or disabletransmission of the phase detection data from the image sensor.
 26. Thecomputer readable medium of claim 25, wherein the code for causing theautomatic focusing module to dynamically enable transmission of thephase detection data from the image sensor comprises: code for causingthe automatic focusing module to enable transmission of the phasedetection data from the image sensor in response to detecting a scenechange.
 27. The computer readable medium of claim 26, wherein the codefor causing the automatic focusing module to detect the scene change isbased on one or more of a gyroscope output, automatic exposure control(AEC) exposure information or a sum of absolute differences.
 28. Thecomputer readable medium of claim 25, further comprising code forcausing the automatic focusing module to disable transmission of thephase detection data from the image sensor until detecting a scenechange.
 29. The computer readable medium of claim 25, furthercomprising: code for causing the automatic focusing module to analyzethe phase detection data to determine a lens position after enablingtransmission of the phase detection data from the image sensor inresponse to detecting a scene change; and code for causing the automaticfocusing module to subsequently disable transmission of the phasedetection data from the image sensor.
 30. The computer readable mediumof claim 29, further comprising code for causing the automatic focusingmodule to perform a fine search to determine a final lens position afterdisabling transmission of the phase detection data from the imagesensor.